scholarly journals Biogenic Silver Nanoparticles Decorated with Methylene Blue Potentiated the Photodynamic Inactivation of Pseudomonas aeruginosa and Staphylococcus aureus

Pharmaceutics ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 709 ◽  
Author(s):  
Paramanantham Parasuraman ◽  
Thamanna R. Y ◽  
Chitra Shaji ◽  
Alok Sharan ◽  
Ali H. Bahkali ◽  
...  

The persistence of multidrug resistance among microorganisms has directed a mandate towards a hunt for the development of alternative therapeutic modalities. In this context, antimicrobial photodynamic therapy (aPDT) is sprouted as a novel strategy to mitigate biofilms and planktonic cells of pathogens. Nanoparticles (NPs) are reported with unique intrinsic and antimicrobial properties. Therefore, silver NPs (AgNPs) were investigated in this study to determine their ability to potentiate the aPDT of photosensitizer against Staphylococcus aureus and Pseudomonas aeruginosa. Biologically synthesized AgNPs were surface coated with methylene blue (MB) and studied for their aPDT against planktonic cells and biofilms of bacteria. The nano-conjugates (MB-AgNPs) were characterized for their size, shape and coated materials. MB-AgNPs showed significant phototoxicity against both forms of test bacteria and no toxicity was observed in the dark. Moreover, activity of MB-AgNPs was comparatively higher than that of the free MB, which concludes that MB-AgNPs could be an excellent alternative to combat antibiotic resistant bacteria.

2021 ◽  
pp. 1-22
Author(s):  
Maryam Afridi ◽  
Saeed Ahmad Khan ◽  
Ruqayya Afridi ◽  
Farman Ullah ◽  
Abdul Majid ◽  
...  

Growing resistance to currently approved antibiotics is posing serious concern worldwide. The multidrug-resistant organisms are a major cause of mortality and morbidity around the globe. The limited options to treat infections caused by resistant organism requires alternative strategies to increase the effectiveness of antibiotic for better clinical outcomes. Recent advances in nanotechnology have enabled the drugs to be used in nanoscale to increase the effectiveness of antibiotics. The use of nanoparticles to treat infectious diseases has a long history in the pharmaceutical market, and the versatility of these particles to incorporate various materials as carriers make it an attractive option to combat the current crisis of emerging antibacterial resistance. Silver, a metal with many medical applications, has inherent antimicrobial properties. Therefore, silver NPs are appearing as one of the best options to be used in combination with antibiotics to increase effectiveness against resistant bacteria. Here, we discuss the applications and mechanisms of silver NPs to treat microbial resistance in light of recent research.


2003 ◽  
Vol 7 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Patricia M. Mertz ◽  
Stephen C. Davis ◽  
Alejandro L. Cazzaniga ◽  
Anna Drosou ◽  
William H. Eaglstein

Background: Besides enhancing healing, an ideal dressing should prevent invasion of pathogens and control the number of bacteria already present in the wounds. Objective: To evaluate the barrier and antimicrobial properties of a cyanoacrylate-based bandage (LAB) against Staphylococcus aureus or Pseudomonas aeruginosa on partial thickness wounds in swines. Methods: Barrier study: Bacteria were inoculated over test materials (LAB, standard bandage, air-exposed) that were placed over wounds. The bacteria from wounds were quantitated at 24, 48, and 72 hours postinoculation. Antimicrobial study: Wounds inoculated with bacteria were covered with LAB, standard bandage, or hydrocolloid bandage or left air-exposed. The bacteria recovered from wounds were quantitated at 24 and 72 hours after treatment. Results: Barrier study: No bacteria were recovered from LAB-treated wounds. Antimicrobial study: LAB reduced the number of inoculated bacteria in comparison to all other groups. Conclusion: LAB is effective in protecting wounds from external bacterial invasion and reducing bacterial contamination.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Pavithra L. Jayatilake ◽  
Helani Munasinghe

Endophytic and rhizosphere fungi are understood to be aiding the host plant to overcome a range of biotic and abiotic stresses (nutrition depletion, droughts, etc.) hence, they remain to be reservoirs of plethora of natural products with immense use. Consequently, this investigation of endophytic and rhizosphere fungi isolated from Mikania cordata (a perennial vine that is well established in Sri Lanka) for their antimicrobial properties was performed with the aim of future derivation of potential beneficial pharmaceutical products. Leaves, twigs, and roots of M. cordata were utilized to isolate a total of 9 endophytic fungi out of which the highest amount (44%) accounted was from the twigs. A sample of the immediate layer of soil adhering to the root of M. cordata was utilized to isolate 15 rhizosphere fungi. Fusarium equiseti and Phoma medicaginis were endophytes that were identified based on colony and molecular characteristics. The broad spectrum of antimicrobial activity depicted by F. equiseti (MK517551) was found to be significantly greater (p≤0.05, inhibitory against Bacillus cereus ATCC 11778, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) than P. medicaginis (MK517550) (inhibitory against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 25853) as assessed using the Kirby-Bauer disk diffusion method. Trichoderma virens and Trichoderma asperellum were rhizospere fungi that exhibited remarkable antimicrobial properties against the test pathogens chosen for the study. T. asperellum indicated significantly greater bioactivity against all four bacterial pathogens and Candida albicans ATCC 10231 under study. The ranges of minimum inhibitory concentrations (MICs) of the fungi depicting antimicrobial properties were determined. The results obtained suggest that F. equiseti, P. medicaginis, T. asperellum, and T. virens of M. cordata harness bioprospective values as natural drug candidates. This is the first report on isolation and evaluation of the antimicrobial properties of endophytic and rhizosphere fungi of Mikania cordata.


2020 ◽  
Vol 31 ◽  
pp. 101810
Author(s):  
Vanesa Pérez-Laguna ◽  
Isabel García-Luque ◽  
Sofía Ballesta ◽  
Luna Pérez-Artiaga ◽  
Verónica Lampaya-Pérez ◽  
...  

Pathogens ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 12 ◽  
Author(s):  
Majed Masadeh ◽  
Karem Alzoubi ◽  
Wesam Ahmed ◽  
Aisha Magaji

An in vitro overview of the inhibitory effects of selected fluoroquinolones against planktonic and biofilm cells of the methicillin-resistant Staphylococcus aureus (MRSA) strain American type culture collection (ATCC) 43300 and the Pseudomonas aeruginosa strain ATCC 27853 was carried out. Biofilm cells of both strains were less susceptible to the selected antibiotics than their planktonic counterparts. In addition, certain antibiotics were more effective against biofilm cells, while others performed better on the planktonic cells. Against P. aeruginosa, ciprofloxacin was the most potent on both planktonic and biofilm cells, whereas ofloxacin was the least potent on both biofilm and planktonic cells. Moxifloxacin and gatifloxacin were the most potent against both planktonic and biofilm MRSA bacteria, however, not in the same order of activity. Norfloxacin was the least active when tested against both planktonic and biofilm cells. The results of this work are expected to provide insight into the efficacy of various fluoroquinolones against MRSA and Pseudomonas aeruginosa biofilms. This study could form the basis for future clinical studies that could recommend special guidelines for the management of infections that are likely to involve bacteria in their biofilm state.


2021 ◽  
Vol 11 ◽  
Author(s):  
Bokyung Son ◽  
Minsuk Kong ◽  
Yoona Lee ◽  
Sangryeol Ryu

As the incidence of antibiotic-resistant bacteria has become increased, phage endolysins are believed as one of the promising alternatives to antibiotics. However, the discovery of potent endolysin is still challenging because it is labor intensive and difficult to obtain a soluble form with high lytic activity. In this respect, the modular structures of Gram-positive endolysins can provide an opportunity to develop novel endolysins by domain rearrangement. In this study, a random domain swapping library of four different endolysins from phages infecting Staphylococcus aureus was constructed and screened to obtain engineered endolysins. The novel chimeric endolysin, Lys109 was selected and characterized for its staphylolytic activity. Lys109 exhibited greater bacterial cell lytic activity than its parental endolysins against staphylococcal planktonic cells and biofilms, showing highly improved activity in eliminating S. aureus from milk and on the surface of stainless steel. These results demonstrate that a novel chimeric endolysin with higher activity and solubility can be developed by random domain swapping and that this chimeric endolysin has a great potential as an antimicrobial agent.


2020 ◽  
Vol 8 (4) ◽  
pp. 110-115
Author(s):  
Afsaneh Molamirzaei ◽  
Maryam Allahdadian ◽  
Monir Doudi

Background: Using smoke from burning donkey dung has been popular in the treatment of many diseases in Iran. Objective: This study aimed to investigating the antimicrobial properties of donkey dung smoke on multi-drug resistant (MDR) bacteria isolated from urinary infection. Materials and Methods: First, 300 and 200 urine samples were collected from pregnant and non-pregnant women in Isfahan, Iran. Then in each group, 100 bacterial isolates including Escherichia coli, Klebsiella pneumonia, Proteus vulgaris, Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Staphylococcus saprophyticus were isolated. Antibiotic resistant protocol was determined by antibiogram test. Donkey dung was sterilized, disintegrated, and heated. The smokes were concentrated in n-hexane solvent (65%) and were collected after evaporation of the solvent. Finally, the antibacterial activities of the concentrations of 0.25, 0.5 and 1 mg/mL of the smokes were detected using disk diffusion and macrodilution methods. Results: The most abundant MDR isolates causing urinary infections in pregnant and non-pregnant women was Escherichia coli. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of donkey dung smoke on MDR isolates from pregnant women were 0.25 mg/mL and 0.5 mg/mL, respectively. In the case of MDR isolates in non-pregnant women, the MIC of the smoke on Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was 0.25 mg/mL, and the MBC on these isolates was 0.5 mg/mL. Conclusion: The smokes from donkey dung investigated in the present study have suitable potentials for controlling the infections after In vivo analysis.


Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 566 ◽  
Author(s):  
Malgorzata Anna Paduszynska ◽  
Katarzyna Ewa Greber ◽  
Wojciech Paduszynski ◽  
Wieslaw Sawicki ◽  
Wojciech Kamysz

The formation of biofilms on biomaterials causes biofilm-associated infections. Available treatments often fail to fight the microorganisms in the biofilm, creating serious risks for patient well-being and life. Due to their significant antibiofilm activities, antimicrobial peptides are being intensively investigated in this regard. A promising approach is a combination therapy that aims to increase the efficacy and broaden the spectrum of antibiotics. The main goal of this study was to evaluate the antimicrobial efficacy of temporin A and the short lipopeptides (C10)2-KKKK-NH2 and (C12)2-KKKK-NH2 in combination with gentamicin against biofilm formed by Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA). Peptides were synthesized with solid-phase temperature-assisted synthesis methodology. The minimum inhibitory concentrations (MICs), fractional inhibitory concentrations (FICs), minimum biofilm eradication concentrations (MBECs), and the influence of combinations of compounds with gentamicin on bacterial biofilm were determined for reference strains of SA (ATCC 25923) and PA (ATCC 9027). The peptides exhibited significant potential to enhance the antibacterial activity of gentamicin against SA biofilm, but there was no synergy in activity against planktonic cells. The antibiotic applied alone demonstrated strong activity against planktonic cells and poor effectiveness against SA biofilm. Biofilm formed by PA was much more sensitive to gentamicin, but some positive influences of supplementation with peptides were noticed. The results of the performed experiments suggest that the potential application of peptides as adjuvant agents in the treatment of biofilm-associated infections should be studied further.


Sign in / Sign up

Export Citation Format

Share Document